WORCESTER — Two people were arrested Thursday morning and charged with using heroin in a City Hall bathroom.

The arrest came after police had been watching drug sales take place blocks away, near 700 Main St., Thursday morning.

Officer Jason P. Gaumond said he saw two people he knew to be involved in the drug trade chatting with a man and a woman around 8 a.m. The officer followed them in his cruiser to the Chandler Street area, where, he said, he believed a drug transaction took place.

Officer Gaumond then followed the two people who he believed bought the drugs, according to a statement of facts on file in Central District Court.

Records identified them as Allyssa Josephson, 26, of 18 Cargill Ave. and Stevie Rivera, 37, of 25 Queen St.

The two walked from Chandler Street to City Hall and got into an elevator, records said. They got off on the third floor.

Officer Gaumond said he rushed up the stairs and saw them go into a handicapped restroom. He heard the door lock. City Hall has had problems with illegal drug use in bathrooms in the past, the officer wrote.

The officer retrieved a key to the bathroom from the mayor's office and unlocked the door. Mr. Rivera tried to keep the door closed, the officer wrote.

"As I was pushing the door open I observed Josephson holding a needle and syringe in her hand," Officer Gaumond wrote.

The officer was able to get the door open. He said he told Ms. Josephson to drop the needle and syringe, which she did. The officer said he saw a brownish liquid inside, consistent with heroin.

The two were arrested on drug charges. Both were arraigned in Central District Court and released on personal recognizance.

Officer Gaumond said he tried to find the alleged seller, but was unable to do so.